In known furnaces used exclusively for burning waste materials, a charging mechanism for continuously charging the furnace with base materials is positioned on the front, higher end face of a drum provided with a charging opening and performing a rocking movement. The rear, open end of the drum, which is lined with refractory material, opens into the vertically positioned fixed secondary combustion chamber lined with a refractory material. One or more rows of nozzles for introducing the combustion air are centrally arranged on the upper shell portion of the furnace drum in the vicinity of its vertical median plane and extend over at least part of the shell length. An example of such a furnace is shown in Swiss Pat. No. 440,526.
A combined combustion and melting furnace for burning waste materials of all types, particularly garbage, is known in which a trough-shaped base containing material to be burned has an overflow edge for removing the molten slag and is arranged in a tank which is incorporated into the front part of the furnace and which has a horizontal or inclined longitudinal axis, and this tank is adapted to rotate about its longitudinal axis. Oxygen-enriched, preheated combustion air is blown into the furnace combustion chamber and against the trough-shaped base through nozzles which are incorporated into the upper wall portion of the front furnace part and which are directed downwardly from above. An example of such a furnace is found in Swiss Pat. No. 411,198.
However, these known furnaces for only burning or for both burning and melting of waste materials have the disadvantage that, particularly because of the different combustion speeds of the different waste materials, the units downstream of the furnace such as the waste heat boiler, flue gas cleaner and exhauster are subject to a widely fluctuating, that is, non-uniform, flue gas flow. This produces a particularly unfavorable result in the case of a heat utilization (waste heat) boiler designed for a specific and preferably constant flow capacity and thermal efficiency. However, it is also undesirable to dimension the other units downstream of the furnace in accordance with the maximum gas flow.